SPEED CONTROL DIAGNOSTICS—W/O SCP
FORD:
2000-2003 Escort
2000-2004 Crown Victoria, Mustang
2000-2005 Focus, Taurus
2000-2001 Explorer
2000-2004 E-Series, Expedition, F-150,
F-Super Duty
2000-2005 Excursion, Ranger
2001-2003 Explorer Sport
2001-2005 Escape, Explorer Sport Trac
2004 F-150 Heritage
ISSUE
Stand-alone speed control system diagnostic
updates have been made in 2006 model year and
newer Workshop Manuals (WSM). These diagnostic
updates also apply to 2000-2005 model year
vehicles. This TSB provides these WSM updates for
2000-2005 model year vehicles.
ACTION
The vehicles in this article are equipped with a
10-pin speed control servo without a standard
corporate protocol (SCP) communication control
system. Follow the Service Procedures and
Diagnostic Tips in this TSB to assist with accurate
diagnosis and repair of speed control issues.
GENERAL SERVICE PROCEDURE
1.
Visually inspect the vehicle. Any after market
modifications, including but not limited to those
listed below, may cause speed control to not
operate correctly:
• Any wiring or lamp modifications affecting
brake lamp operation
• LED brake lamps
• Non-factory installed trailer wiring
• Radios (speed sensitive, auto mute)
• Remote starters and alarms
• Lighting and electrical accessories
modifications
TSB 06-8-5
LINCOLN:
2000-2002 Navigator
2001-2002 Blackwood
MERCURY:
2000-2002 Cougar
2000-2004 Grand Marquis
2000-2005 Sable
2003-2004 Marauder
2000-2001 Mountaineer
2005 Mariner
2.
Visually inspect the servo and accelerator
controls:
• Visually inspect speed control cable without
removing and ensure smooth cable operation.
Inspect cable connection to the throttle body
• Visually inspect accelerator cable without
removing and ensure smooth cable operation.
Inspect cable connection to throttle body.
Also check for interference with carpet,
bulkhead grommet, insulation, and instrument
panel wiring
SERVICE PROCEDURE
Start by running speed control servo integrated self
test diagnostics. The servo has integrated self test
diagnostics which is a key tool in quickly and
accurately diagnosing speed control system faults.
Self test diagnostics are also the basis for starting
speed control trouble shooting.
WARNING
THIS TEST IS A KEY ON ENGINE OFF (KOEO)
TEST THAT IS CONDUCTED ONLY WHILE
PARKED WITH THE PARKING BRAKE FULLY
ENGAGED. FAILURE TO FOLLOW THESE
INSTRUCTIONS MAY RESULT IN PERSONAL
INJURY.
NOTE: The information in Technical Service Bulletins is intended for use by trained, professional technicians with the knowledge, tools, and equipment to do
the job properly and safely. It informs these technicians of conditions that may occur on some vehicles, or provides information that could assist in proper
vehicle service. The procedures should not be performed by “do-it-yourselfers”. Do not assume that a condition described affects your car or truck. Contact a
Ford, Lincoln, or Mercury dealership to determine whether the Bulletin applies to your vehicle. Warranty Policy and Extended Service Plan documentation
determine Warranty and/or Extended Service Plan coverage unless stated otherwise in the TSB article.The information in this Technical Service Bulletin
(TSB) was current at the time of printing. Ford Motor Company reserves the right to supercede this information with updates.The most recent information is
available through Ford Motor Company’s on-line technical resources.
Copyright  2006 Ford Motor Company Online Publication Date April 6, 2006
PAGE 1
TSB 06-8-5 (Continued)
NOTE
THE SELF-TEST IS COMPRISED OF TWO
PARTS. THE FIRST PART IS A STATIC CHECK
OF THE SPEED CONTROL ELECTRONICS
MODULE AND SYSTEM. THE SECOND PART IS
A DYNAMIC PULL-TEST TO CHECK THE
ACTUATOR MOTOR AND GEAR MECHANISM.
NOTE
THE MODULE TIMES OUT IF EACH BUTTON IS
NOT PRESSED WITHIN 1 SECOND OF THE
PREVIOUS BUTTON. IF A MODULE TIME OUT
OCCURS (SPEED CONTROL LAMP STOPS
FLASHING PART WAY THROUGH THE TEST),
THE PROCEDURE MUST BE RE-INITIATED.
NOTE
ON VEHICLES EQUIPPED WITH A MANUAL
TRANSMISSION, THE CLUTCH PEDAL SHOULD
NOT BE DEPRESSED EXCEPT FOR
ESCAPE/MARINER, WHICH SHOULD BE
DEPRESSED, IN ORDER TO CORRECTLY
PERFORM THE SELF-TEST. ON VEHICLES
EQUIPPED WITH AN AUTOMATIC
TRANSMISSION, THE TRANSMISSION
SELECTOR LEVER NEEDS TO BE IN THE “P”
POSITION FOR THE SELF TEST EXCEPT FOR
THE ESCAPE/MARINER WHICH SHOULD BE IN
“N”.
NOTE
REVIEW THE FOLLOWING STEPS BEFORE
CARRYING OUT THE SELF-TEST DIAGNOSTIC
PROCEDURE.
1.
Self Test Diagnostic Procedure - Static Test
a. Connect the diagnostic scan tool (DST) to a
power source that is not interrupted when
the ignition switch changes positions. With
the ignition switch in the RUN position, set
the DST to monitor the powertrain control
module (PCM) throttle position PID while the
speed control actuator carries out the
self-test.
b. Enter self-test diagnostics by firmly pressing
and holding the speed control OFF switch
while quickly cycling the ignition switch from
RUN-to-OFF-to-RUN, making sure the
engine does not start and is not running.
PAGE 2
c. The speed control indicator lamp on the
instrument panel will flash once to indicate
that the speed control module has entered
the self test diagnostic mode. Release the
OFF switch. If 5 flashes are displayed at
this point, a speed control subsystem
concern exists. Refer to the Symptom Chart
in the vehicle WSM.
d. Then firmly press and release the remaining
switches WITHIN 1 SECOND of each other
in the sequence below. The speed control
indicator lamp flashes once after each of the
buttons is successfully pressed.
Figure 1 - Article 06-8-5
NOTE
MONITOR THE PCM THROTTLE POSITION PID
AFTER THE LAST BUTTON IS PRESSED.
NOTE
THERE WILL BE A SLIGHT DELAY FROM WHEN
THE LAST BUTTON IS PRESSED AND THE
CLUSTER LAMP FLASHES DIAGNOSTIC CODES.
NOTE
IF THE SELF-TEST WILL NOT START OR
CANNOT BE COMPLETED AFTER MULTIPLE
ATTEMPTS, GO TO THE VEHICLE WSM
SYMPTOM CHART.
e. Follow the list below for diagnostic flash
codes, then go to the WSM Symptom Chart.
TSB 06-8-5 (Continued)
Figure 2 - Article 06-8-5
2.
Self Test Diagnostic Procedure - Dynamic Test
NOTE
THE DYNAMIC TEST OCCURS AUTOMATICALLY
AFTER THE STATIC TEST PASSES. IF THE
STATIC TEST FAILS RESULTING IN FLASH
CODES, THERE WILL BE NO DYNAMIC PULL
TEST.
a. Within .25 seconds after the static test has
completed, the speed control actuator
carries out a dynamic pull test. The actuator
automatically pulls the speed control cable
.04 to .39″ (1 to 10 mm) to move the
throttle from the idle position and then
releases the speed control cable returning
the throttle to the idle position.
NOTE
THE 2001-2005 ESCAPE/MARINER HOLDS THE
PEAK THROTTLE PULL FOR 3 SECONDS PRIOR
TO RELEASING.
b. If the throttle position PID voltage value
does not change during the dynamic throttle
pull, go to the WSM Symptom Chart Section
for Dynamic Pull Test failure.
SPEED CONTROL DIAGNOSTIC TIPS
Servo Pin-Out Test Tips
NOTE
MEASURING THE RESISTANCE OF A SERVO
WILL INDICATE THAT A SERVO IS BAD IF
READINGS ARE OUTSIDE THE RANGES
SPECIFIED BELOW. HOWEVER, A SERVO CAN
HAVE RESISTANCE READINGS WITHIN THE
SPECIFIED RANGES AND STILL BE FAULTY.
The following readings are the expected values for
a good servo.
Resistance between Pins 6 and 10 should measure
less than 5 ohms. This is the ground circuit through
the module. Resistance between Pins 7 and 10 will
vary with polarity, the type of meter, and source
voltage of the meter. Also measurements between
Pins 7 and 10 can be any of the following: an open
circuit, increasing reading (as a capacitor charging),
or changing value (re-apply leads and different
value indicated), or a stable reading of 10,000 ohms
or greater are all valid results as this is a solid
state circuit.
DST Testing Tips (TPS PID)
1.
Pinpoint Test: The Speed Control Does Not
Disengage When The Brakes Are Applied
PAGE 3
TSB 06-8-5 (Continued)
With the vehicle speed above 30 MPH (48 Km/h)
engage the speed control. Then check to see if the
TPS PID returns to base voltage when the brakes
are applied. If it does return to base voltage, then
the speed control system is working. Need to
advise customer that tapping the brakes deactivates
speed control and that the brakes must be applied
to make the vehicle slow down. On the
Escape/Mariner the brake pedal should be
depressed at least 13/32″ (10 mm) in order to
deactivate speed control.
NOTE
CHECK FOR CALIBRATION SERVICE MESSAGES
RELATING TO DASHPOT OR IDLE SPEED
CONTROL UPDATES.
2.
Pinpoint Test: The Speed Control Does Not
Disengage When The Clutch Is Applied
Check to see if the TPS PID returns to base
voltage when the clutch is pressed. If it does then
the speed control system is working. Need to
advise customer that pressing clutch deactivates
speed control and that the brakes must be applied
to make the vehicle slow down.
NOTE
CHECK FOR CALIBRATION SERVICE MESSAGES
RELATING TO DASHPOT OR IDLE SPEED
CHANGES. ALSO A SLIGHT ENGINE RPM FLARE
MAY OCCUR ON SOME VEHICLES WHEN
SPEED CONTROL IS DISENGAGED WHICH IS A
NORMAL CONDITION.
Speed Signal Testing Tips
NOTE
A FAULTY VEHICLE SPEED SIGNAL TO THE
SERVO CAN RESULT IN INTERMITTENT,
IRREGULAR OR INOPERATIVE SPEED
CONTROL.
NOTE
FOR VEHICLES THAT HAVE OSS OR HALL
EFFECT VEHICLE SPEED SIGNALS TO THE
SERVO, REFER TO WSM FOR DIAGNOSTICS.
To verify that the speed control signal sent to the
servo is valid, the following inspection may be done
for ABS and PCM generated speed signals:
1.
Disconnect speed control module (C122).
2.
Connect DVOM set to Hz to C122 Pin 3
harness side and C122 Pin 10 (ground)
harness side.
PAGE 4
3.
Start the vehicle; place the transmission in
DRIVE, test drive vehicle between 25-30 MPH
(40-48 Km/h).
4.
Measure the frequency between the speed
control actuator C122 Pin 3 harness side and
C122 Pin 10 (ground) harness side. Divide
frequency by 2.2 to give MPH and compare to
speedometer reading. Measure AC Volts and
record.
5.
If the AC Voltage is greater than 4.5V and the
frequency reading does match the speedometer
reading then the speed signal is valid. If further
diagnostics are required see WSM.
Deactivator Switch Inspection Tips
A faulty deactivator switch can result in intermittent
or inoperative speed control. There are two types of
deactivator switches; a brake line pressure switch,
which is integrated into the brake master cylinder,
and a pedal travel switch, which is connected to the
brake pedal arm.
Proper switch function should be confirmed.
Inoperative switches of both types should be
inspected for connector corrosion or pin push-out.
Pedal travel switches should also be inspected for
proper mechanical adjustment relative to brake
pedal travel.
ADDITIONAL REFERENCE INFORMATION
Speed Control Servo Operation and Function
NOTE
ALL FUNCTIONALITY LISTED BELOW IS
PERFORMED WITH CONNECTORS CONNECTED
AND KEY IN RUN POSITION UNLESS
OTHERWISE NOTED.
PIN 1 - Indicator. (if used) Speed control servo
grounds this circuit to turn the speed control lamp in
cluster on during operation. This will not affect
operation of system.
PIN 2 - Clutch/TRS Input. (Escape/Mariner only)
Signal comes from clutch switch (MT) or TRS (AT).
On the harness side the signal can be measured by
connecting a DVOM, set to ohms, between Pins 2
and B-. With clutch depressed (MT) or in N (AT)
you should read 0 ohms, which disables speed
control. With clutch released (MT) or in D (AT)
signal should read greater than 10,000 ohms, which
enables speed control operation.
TSB 06-8-5 (Continued)
PIN 3 - VSS Input. (Note: Performed with engine
running and vehicle driven.) Signal comes from
PCM, ABS, OSS, hall effect sensor depending on
application. Except for hall effect sensor, the signal
can be measured by removing Connector C122 and
measuring the frequency between Pins 3 and 10
with a DVOM set to AC Hz. The signal should
measure 2.2 Hz/MPH. The vehicle must be traveling
30 MPH (48 Km/h) before the system will set,
therefore a minimum of 66 Hz must be observed.
Take note that on vehicles equipped with SVC
(speed sensitive volume control), an internal
problem within the radio can bring signal down to 0
Hz even though it reads correctly in PCM PIDs. If
signal is missing disconnect radio and retest. Note,
for vehicles with a hall effect input to the speed
control servo, see WSM for speed signal
verification.
PIN 4 - Brake Switch Input (BOO/BPP).
NOTE
ENSURE THAT BRAKE LAMPS ARE
FUNCTIONING CORRECTLY.
Vehicles with automatic transmission and all Escape
and Mariner vehicles (auto and manual): With a
DVOM set to ohms, measure resistance between
Pins 4 and B- with brake pedal not depressed, you
should get less than 5 ohms. Then measure voltage
with brake pedal depressed, you should get 12 V.
Operation: The servo sends out a reference voltage
on Pin 4 (4-7V) which is grounded through the
brake lamps or switched directly to ground.
Vehicles with manual transmissions (except Escape
and Mariner vehicles, see above): With a DVOM set
to ohms, measure resistance between Pin 4 and Bwith brake pedal not depressed and clutch pedal
not depressed, you should get less than 5 ohms.
Next, depress clutch pedal only, measuring
resistance, you should get an open circuit / infinite
resistance. Then measure voltage with brake pedal
depressed, clutch pedal not depressed and you
should get 12 V. Repeat with both pedals
depressed and you should get 0 volts. Operation:
The servo sends out a reference voltage on Pin 4
(4-7V) which is grounded through the brake lamps
or switched directly to ground when the clutch pedal
is not depressed.
PIN 5 - Control Switch Input. (Note: Performed with
key in OFF position.) Remove Connector C122,
using a DVOM set to resistance, measure the
resistance between Pins 5 and 6. See table of
resistance readings below for each switch when it is
depressed.
Figure 3 - Article 06-8-5
PIN 6 - Control Switch Return. This is the return
side of the switches, which are grounded internally
to the servo to Pin 10. If test for Pin 5 checks good
then Pin 6 is functioning normally.
PIN 7 - Power. Remove Connector C122, Using a
DVOM set to DC volts, measure the voltage
between Pin 7 and ground. You should read greater
than 10 volts with the key in the run position.
Record the voltage from Pin 7 to ground, then
re-measure with a test lamp (1156) from Pin 7 to
ground, to ensure current carrying capability. The
difference between the two measurements should
be less than 0.3 VDC. If voltage drop test fails then
check wiring.
PIN 8 - Not used.
PIN 9 - Brake Deactivator Switch (BPS). This is a
redundant shutoff switch. Without depressing the
brake pedal, measure voltage on Pin 9, and
re-measure with a test lamp (1156) from Pin 9 to
ground, to ensure current carrying capability. The
difference between the two measurements should
be less than 0.3 VDC. The system requires enough
current at this pin to engage properly. If voltage
drop test fails, check for corroded wiring or
deactivation switch. You should measure 0 volts at
Pin 6 when the brake pedal is depressed firmly.
An alternate to the voltage drop test would be to
disconnect the switch connector and measure the
switch resistance. It should be less than 5 ohms. If
the switch is suspected, a bypass test may also be
done: On the harness side of the BPS connector,
connect a jumper between the two deactivation
switch pins and drive vehicle above 30 MPH (48
Km/h). If speed control engages then the brake
deactivation switch was faulty, otherwise wiring is at
fault.
PAGE 5
TSB 06-8-5 (Continued)
PIN 10 - Ground. Using a DVOM set to DC volts,
measure the voltage between B+ and Pin 10. You
should read greater than 10 volts. Record the
voltage between B+ and Pin 10 , then re-measure
with a test lamp (1156) from B+ to Pin 10. The
difference between the two measurements should
be less than 0.3 VDC. If voltage drop test fails then
check wiring. This verifies circuit can carry proper
load as well as continuity to ground.
WARRANTY STATUS: Information Only
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